Today, I ran my first half-marathon, the Great Eastern Run in Peterborough. 13.1 miles, to raise money for Amnesty International. Read on for my experience as a first-timer!

The day didn't start in a very promising manner. Getting to Peterborough from Cambridge on a Sunday morning is surprisingly difficult; coaches run slowly and infrequently, and to get there before 11am by train required changing at Stevenage - twenty miles in the wrong direction! Catching a train before 8:30am is never a great start to a day, but the real fun started at Stevenage: "The 9:20 train [...] has been delayed by over-running engineering works...". A small group of increasingly anxious runners stood in light drizzle, waiting for our train, for almost an hour. Network Rail's usual fine standard of service.

As a consequence, we arrived in a rather sunnier Peterborough just a few minutes before the start. After a dash from the station which also had to double as a warm-up, I reached the start literally as the race got underway. Runners were organised by target finishing time, but as I arrived as the crowd was starting to roll I was right at the back. This turned out to be a sure-fire way to prevent me going off too fast; the first mile was spent zig-zagging through the crowd, dodging through gaps when they appeared. At a couple of points I even ended up walking, when everyone was bunched up and there was literally no space to run into.

After another mile or so the race had opened up a bit more, and I built up to a normal pace. The weather was good for running - cool and mostly dry - and there were plenty of people out in the sidelines cheering, giving a great atmosphere to the race. The mile markers started passing surprisingly quickly - four miles, five miles, six miles, the half-way marker. It wasn't until the seven-mile marker that the pains started sparking up. As usual, the left leg was the problem: the ankle started giving a bit of a twinge if I struck a bit too flat. By the eight-mile mark, the hips were complaining, and a blister was starting on one foot - oddly, as I'd never had a problem with it during training. Still a fair way to go, keep pushing.

By this point, the race was pretty open. I was still passing quite a few people, but now in slow-motion. A few people came past me - some whom must have been late to the start, as they were clearly running sub-1:30 times, and a pair who were doing a curious sprint-drift pattern. They'd come past in a hurry, at speed - and then a few minutes later I'd overhaul them again running at a steady pace. This happened three or four times, until at about 11 miles they fell back. By now, my legs were starting to really tire, but I was far from out of breath. In fact, with 2 miles to go I decided that I could afford to pick up the pace further, and started passing a lot of people who'd done the opposite and gone off fast. There was a bit of an unsettling moment passing an apparently unconscious girl with paramedics around her - hard to tell what had happened. Past the twelve mile mark. Keep pushing!

The last mile was the fastest, as I knew I no longer needed to keep anything in reserve. Coming along the last section by the park, I felt great - running properly fast, sore legs didn't matter. Coming into the home straight, I even managed a sprint finish, burning everything I had left in the tank. I crossed the finish line at what I think was 1 hour 49'04. When I stopped I found my legs had decided they'd done enough for now - they'd gone slightly jellylike, and I had to find a railing to lean against for a minute to pull myself together before going to pick up my finisher's medal and goody bag.

All in all, I was pretty happy with the time (I'd previously decided that anything under 2 hours would be fine). I could probably have done faster if the first couple of miles had been more according to plan, and if I ran it again I would have a better feel for the right pace to set, but ultimately by the end I'd pushed myself about as hard as I could - and this is one of the reasons I enjoy running. There are few things you can do that are so simple, but in doing them you can push yourself right to the edge of the envelope. In summary, a very good experience, and a fair amount raised for my favourite charity - loads of thanks to everyone who's already donated, and for those who haven't, you're not too late!

On the 11th October, I'm running my first ever half-marathon, the Great Eastern Run at Peterborough.

I'm using this as an opportunity for my friends and colleagues - wonderful people that they are! - to support a wonderful charity, Amnesty International. Amnesty International are dedicated to supporting human rights, and protecting individuals wherever justice, fairness, or freedom are denied.

So please help me reach my target by donating at http://www.justgiving.com/Chris-Cunningham